Using the haul while the line is in the water is NOT as effective as waiting until the rod is as loaded as it is going to get in the regular cast. That last little bit of load at the very end is where you increase and maintain the effect of the haul.
The rod will straighten after the haul if done too early and it will not increase line speed, the whole point of hauling.
Also, the haul is very simple, a short tug of 8" or so of line which is IMMEDIATELY returned.
The monster forward haul often seen in saltwater fly fishing does more than the 8" quickie, for sure, but the compromises are not usually worthwhile in freshwater fly casting... big water steelhead is an exception.
A tune-up from a good teacher will improve distance remarkably.
